In a web printing press, a web or webs may be printed in various printing units. The webs then may enter a folder superstructure. There the webs may be slit into ribbons, which are then superimposed to form a ribbon bundle before passing to a former. The ribbon bundle in the folder superstructure may be drawn over a roller at the top of the former called an RTF by driven nip rolls located after the nose of the former. The ribbon bundle then may pass to folder where the ribbon bundle is cut into signatures.
The signatures can then be transported between a plurality of upper and lower transport tapes for further processing. The upper and lower transport tapes are driven by rollers. During transport, and particularly when the transport direction of the signatures is changed as they pass over roller(s), skew is introduced into the signatures. In general, the skew develops due to the difference in the path length of the inner sheet verses the outer sheet as it passes around a roller.
Commonly owned U.S. Published Patent Application 2008/0150208, entitled “Compressible nip rolls for Multiribbon transport” discusses the use of microcellular rolls for main nips located at the bottom of formers and commonly owned U.S. application Ser. No. 12/587,972, filed Oct. 15, 2009 and entitled “Compressible Roll Top of Former for Multiribbon Transport” discusses the use of microcellular rolls as the nip rollers top of formers (RTF). In both cases, a continuous web passes through the microcellular rolls.